Boston University Slideshow Title Goes Here
Achieving Energy Efficiency in Buildings
Michael Gevelber, Associate Professor
Mechanical Engineering
Co-chair, BU Energy Committee
Member, BU Sustainability Committee
gevelber@bu.edu
•Results of BU Energy Audit Course
•Overview of US Building Energy Use
•Achieving Energy Efficiencies in Commercial Buildings
•Residential: Perform your own energy audit
Advanced Control Research Application Areas
Boston University Slideshow Title Goes Here
Plasma Spray: TBC’s & Fuel Cells
H
V
H
Crystal Growth
P
Ebeam deposition: optical coatings
Electrospinning: nanofiber
What’s Global Warming & What
Causes it?
Boston University Slideshow Title Goes Here
Boston University Sustainable Neighborhood Living Lab
Summary of Findings from GE 520/MN 500: “Energy
Audit/Conservation Analysis of BU’s Charles River Campus”
Boston University Slideshow Title Goes Here
2008
2009
2010
Michael Gevelber, Associate Professor Mechanical
Engineering, co-chair BU energy working group, member of
BU Sustainability Comm & CEESI
Results of 2007 Energy Audit
Boston University Slideshow Title Goes Here
Total Energy Use
Energy Intensity (Per Sq Foot)
1.6E+12
1.4E+12
160
68% Growth in Energy Use
18% Increase in Energy Intensity
150
Natural gas
Btu
1.0E+12
8.0E+11
Electricity
6.0E+11
4.0E+11
Light oil
Btu/sq. foot (1000)
1.2E+12
140
130
120
110
2.0E+11
Heavy oil
0.0E+00
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
100
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
• What are the reasons for these trends?
• What can be done to reverse these trends?
Cleveland, C. (2007, Oct 24). Energy and Emissions Footprint: Boston University Charles River Campus. Presentation to the BU
Energy Club.
Building Energy Use by Fuel
Charles River Campus
2005-2007
Boston University Slideshow Title Goes Here
Energy Supply
106 kBtu
Energy Expenses
Boston University Slideshow Title Goes Here
Overview of US Building Energy Use
Boston University Slideshow Title Goes Here
Energy Use/Inefficiencies of US End-Use Sectors
In Quads
Boston University Slideshow Title Goes Here
Residential
21.6
22%
Commercial
18.5
31.2
Waste
9.2
27.9
28%
Buildings
account for
~40% of
energy use!
73% of
electricity
use
6.7
12 (39%)
Waste
31%
Transportation
11.7 (63%)
Waste
19%
Industrial
12.4 (57%)
Major opportunity is
focusing on
efficiences
19.2
21 (75%)
Waste
6.9
Based on llnl energy flow charts
Energy Use/Inefficiencies in
Residential and Commercial Sectors
Input (Quads)
Boston University
11.5Here
Q Direct Use
Electricity:
4.7 direct Slideshow Title Goes
(Electricity Generation
21.6 Quads Total
Waste: 10.2)
Heating
Gas: 5
Oil:1.2
Biomass: .5
Total: 21.6
Waste (Q)
Residential
22% of U.S. Energy
use
Heating ~58% of direct
31% overall
Direct Waste: 2.3 (20%)
Waste
Electricity Waste: 10.2
Total: 12.5 (57%)
Use
9.2 to end-use (43%)
Direct waste assumes 80%
combustion efficiency.
Question: Is that really the
Electricity: 4.6
(Electricity Generation
Waste: 10)
Heating
Gas: 3.2
Oil: 0.6
Coal and Biomass: 0.1
Total: 18.5
Commercial
total waste?
Direct Waste: 1.7 (20%)
8.6 Quads Direct
18.5 Quads Total
Waste
19% of U.S. Energy use
Heating ~ 45% overall
Electricity Waste: 10
Total: 11.7 (63%)
Use
6.7 to end-use (37%)
Where are the opportunities for greater efficiency?
* 1 Quad (Q) = 1015 BTU
Energy Savings: Solving for the Hidden Costs of HVAC
Achieving Energy Efficiency in Existing Commercial Buildings
Boston University Slideshow Title Goes Here
Our Focus:
HVAC is 50-70% of ALL energy
used in mid/large size buildings
Strategy:
Reduce high air flow rates which were
implemented when energy was cheap.
Our Solution
• Develop new tool to re-optimize HVAC control
• This is not addressed by current tools
• Based on real buildings, experience and data
Funded by MA Clean Energy Center
Professor Gevelber & Professor Wroblenski
BU Mechanical Engineering
Boston University team Aeolus: MIT Clean
Energy Contest -Winners of Energy
Efficiency track. 2013
Boston University Sustainable Neighborhood Living Lab
Boston University Slideshow Title Goes Here
Residential: Perform Your Own
Energy Audit
How to Become an Energy Detective:
Help save the world and make some
money at the same time
Prof. Michael Gevelber
Michael Cannamela, Ph.D Candidate,
Mechanical Engineering
Boston University Sustainable Neighborhood Living Lab
Home Energy Audit
Boston University Slideshow Title Goes Here
INPUTS
Yearly Usage
ELECTRICITY
HEATING
0
kWh/yr
gas
0
therms/ yr
oil
0
gal/yr
0
miles/yr
20
mpg
0
miles/yr
20
mpg
0
miles/yr
20
mpg
car #1
TRANSPORT
car #2
car #3
SIZE
ft2
area
occupancy
LOCATION
ENERGY
PRICES
Unit
0
MA
persons
-
electricity
0.174
$/kwh
gas
1.63
$/therm
oil
2.9
$/gal
gasoline
3
$/gal
COMPARISON
RESULTS
yearly
use
unit
% total
use
electricity
0
28775
<----MA average
heat
0
86165
<----MA average
transport
0
TOTAL
0
electricity
0
heat
0
transport
0
TOTAL
0
32
<----US average (4
person
house)
electricity
0
heat
0
transport
0
TOTAL
0
ENERGY
Boston University Slideshow TitlekBtu/yr
Goes Here
CO2
MONEY
tons/yr
$/yr
electricity
HOUSE
EFFICIENCY
PER AREA
value
heat
TOTAL
kBtu/yr/ft2
How much energy and
carbon your household
uses and for what enduses?
How much money you
spend on different forms of
energy? Helps to
understand what efficiency
investments have good
payback?
What is the relative
efficiency [kbtu/ft2] of your
house?
Which areas can more
easily be made more
efficient?
12.87
<----MA average
MA AVG
38.54
<----MA average
House size
51.40
<----MA average
2236
ft2
Occupancy
2.55
persons
Boston University Slideshow Title Goes Here
Boston University Slideshow Title Goes Here
Why focus on energy: what problems
does the US face?
• Limited energy supply & global politics
– U.S. is only 5% of world population but consumes
20% of world energy
• Pollution and Green House Gas emissions
• $ energy is getting more expensive
How do we know where to focus?
• What major fuels/energy do we use
– Electricity
- fuel: combustion
- oil -natural gas
- gasoline
• What are the major end-use applications
– House
- fuel
- transportation
- electricity
Total Annual Energy Cost
Annual Cost of Energy
4.5
4
3.5
Frequency
3
2.5
2
1.5
1
0.5
0
Cost ($)
• Being more energy efficient to reduce our
carbon footprint also saves $$$$
How’s Goldner’s class doing in
terms of GHG emissions?
Annual CO2 Released
10
9
8
Frequency
7
6
5
Frequency
4
US Average (32)
3
2
1
0
0
5
10
15
20
25
30
35
40
45
Annual CO2 Released (Tons CO2/yr)
But how can we do better?
50
More
Where should we focus on to reduce
energy use?
% of Total Annual Energy Use (From
Oil & Gas)
Frequency
22
20
18
16
14
12
10
8
6
4
2
0
0
10
20
30
40
50
60
22
20
18
16
14
12
10
8
6
4
2
0
0
70
10
20
30
40
50
% of Total Annual Energy Use (From
Gasoline)
22
20
18
16
14
12
10
8
6
4
2
0
0
10
20
30
60
70
80
% of Total Annual Energy Usage
% of Total Annual Energy Usage
Frequency
Frequency
% of Total Annual Energy Use
(From Electricity)
40
50
60
70
% of Total Annual Energy Usage
80
90
100
More
90
100 More
Energy Use in Your House
• How compare relative efficiency? KBTU/sq ft
Total Residential Energy Usage Per Unit Area
8
7
Frequency
6
5
4
MA Average (51.40)
3
2
1
0
0
10
20
30
40
50
60
70
80
90
100 110 120 130 140 More
Energy Used (kBtu/yr/ft^2)
• What forms of energy do you use in your house?
• What are you using this energy for?
Household Electricity Use
Electric Energy Usage Per Unit Area
8
7
Frequency
6
5
4
MA Average (12.87)
3
2
1
0
0
3
6
9
12
15
18
21
24
27
30
33
More
Energy Used (kBtu/yr/ft^2)
• What are the major uses of electricity in
your house?
• What are some ways to increase the efficiency
of your electricity use?
Household Natural Gas Use
Oil & Gas Usage Per Unit Area
7
6
Frequency
5
4
3
MA Average (38.54)
2
1
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
Energy Used (kBtu/yr/ft^2)
• What are the major uses of Natural Gas?
• What are the best ways to increase the
efficiency of your gas use?
Distribution of CO2 Sources
Electricity % of Total Annual CO2
Emissions
Fuel % of Total Annual CO2
Emissions
20
15
Frequency
Frequency
20
10
5
0
15
10
5
0
0
10
20
30
40
50
60
70
80
90
100 More
0
10
20
% of Annual CO2 Released
30
40
Frequency
20
15
10
5
0
10
60
70
80
% of Annual CO2 Released
Gasoline% of Total Annual CO2
Emissions
0
50
20
30
40
50
60
70
% of Annual CO2 Released
• Where should we focus?
80
90
100 More
90
100 More
Where focus to reduce energy costs?
Frequency
Cost Percentage (Electricity)
14
12
10
8
6
4
2
0
10
20
30
40
50
60
70
80
90
100
More
% of Total Energy Cost Spent on Electricity
Frequency
Cost Percentage (Oil & Gas)
What’s
surprising?
14
12
10
8
6
4
2
0
10
20
30
40
50
60
70
80
90
100
More
100
More
% of Total Energy Cost Spent on Natural Gas
Frequency
Cost Percentage (Gasoline)
14
12
10
8
6
4
2
0
10
20
30
40
50
60
70
% of Total Energy Cost Spent on Transportation
80
90
The Importance of Screening
Data
• Here is a histogram of the annual gasoline
usage of those who participated in the home
energy audits.
Annual Gasoline Usage
9
8
Frequency
7
6
5
4
3
2
1
0
0
300
600
900
1200 1500 1800 2100 2400 2700 3000 3300 More
Gasoline Usage (Gallons/yr)
• Do these values make sense? What would
be a good way to go about estimating
someone’s average gasoline usage per
year?
• In order to estimate someone’s average gasoline
usage, you would need to know: how many vehicles
they use, how many miles those vehicles can travel
with one gallon of gasoline (mpg), and how many miles
they travel in a year.
• For example:
Someone has 1 car, that gets 20 mpg, and they travel
15000 miles/year. They would use: 15000 (miles/year)
/ 20 (mpg) = 750 (gallons/year).
• Or:
Someone has 1 car, that gets 12 mpg, and they travel
30000 miles/year. They would use: 30000 (miles/year)
/ 12 (mpg) = 2500 (gallons / year)
• Here is that same histogram with the
Environmental Protection Agency’s (EPA)
estimates on average annual gasoline usage.
Annual Gasoline Usage
9
8
7
Frequency
6
5
Frequency
4
US Average for 1 Car
3
US Average for 2 Cars
2
1
0
0
300
600
900
1200 1500 1800 2100 2400 2700 3000 3300 More
Gasoline Usage (Gallons/yr)
• Here is a histogram of the areas of the
different houses that participated in the home
energy audits.
House Areas
12
Frequency
10
8
6
4
2
0
House Area (ft^2)
• Do all of these values make
sense?
• To put things in perspective, Bill Gates’ largest
house is a 66,000 ft^2 mansion in Washington
(2).
• In order to determine if these values are valid, it
might help to look at the Energy Usage Index (EUI).
This is a measure of how much energy is used per
year, per square foot (kBtu/yr/ft^2).
Total Residential Energy Usage Per Unit Area
(Houses)
12
Frequency
10
8
6
Frequency
4
MA Average (51.40)
2
More
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
0
Energy Used (kBtu/yr/ft^2)
• As a reference, the Massachusetts average has been
added to the plot. How would an increase in area of a
house change the EUI? Do you think the energy usage
increase as well?
• The house with the largest area
corresponds to the house with the
lowest EUI. What does this tell you
about the data?
Total Residential Energy Usage Per
Unit Area (Houses)
House Areas
12
Frequency
8
6
4
2
More
42000
39000
36000
33000
30000
27000
24000
21000
18000
15000
12000
9000
6000
3000
0
0
Frequency
10
12
10
8
6
4
2
0
Frequency
MA Average (51.40)
0
20
40
60
80 100 120 140
Energy Used (kBtu/yr/ft^2)
House Area (ft^2)
Same
house
BU Energy Use:
Boston University Slideshow Title Goes Here
LSEB (468)
Energy Cost
CRC
9.3 M ft2
79%
1.2 M ft2
21%
10.5 M ft2
100%
(1)
Total
Average BUMC Energy Density 335
361
300
kBTU/Ft^2
Net Area
BUMC
400
350
FY2007
Photonics (336)
SMG (220)
250
248
226
200
140 BSR (140)
150
Average CRC Energy Density 117
100
50
109
106
72
125
114
141
92
89
72
CRC
- Focus on high energy density buildings
NOTES:
(1) BUMC Net Area does not include NEIDL and rental properties
(2) Data sources from BU energy audit class (M. Gevelber) & Facilities (P. Zhong & A. Ly)
BUMC
BUMC Admin
BUMC Education
BUMC Research
Offices
Classrooms
Labs
Brownstone Offices
Dorms
Apartments
Brownstone Residences
Activity
Retail
0
Original Estimate Updated
Reduce Nighttime Exhaust (8 hrs)
Boston University Slideshow Title Goes Here
Estimate of Potential Setback Savings
Heating oil
savings
Cooling electricity
savings
•Find energy used to condition a
unit volume of air
•Find volume of air exhausted
•Add energy used to condition air
across all units of air exhausted
Estimated Savings
$12,522
21%
•11% of total oil ($7,400)
•7% of total electric. ($10,900)
13%
~$20k
Estimated Implementation Cost
$50k
<2
$17,500—about 1 year payback
$17.5k to Andover
The rest is Rebalance! Was it
needed?
BU Energy Use:
Boston University Slideshow Title Goes Here
LSEB (468)
Energy Cost
CRC
9.3 M ft2
79%
1.2 M ft2
21%
10.5 M ft2
100%
(1)
Total
Average BUMC Energy Density 335
361
300
kBTU/Ft^2
Net Area
BUMC
400
350
FY2007
Photonics (336)
SMG (220)
250
248
226
200
140 BSR (140)
150
Average CRC Energy Density 117
100
50
109
106
72
125
114
141
92
89
72
CRC
- Focus on high energy density buildings
NOTES:
(1) BUMC Net Area does not include NEIDL and rental properties
(2) Data sources from BU energy audit class (M. Gevelber) & Facilities (P. Zhong & A. Ly)
BUMC
BUMC Admin
BUMC Education
BUMC Research
Offices
Classrooms
Labs
Brownstone Offices
Dorms
Apartments
Brownstone Residences
Activity
Retail
0
Original Estimate Updated
Reduce Nighttime Exhaust (8 hrs)
Boston University Slideshow Title Goes Here
Estimate of Potential Setback Savings
Heating oil
savings
Cooling electricity
savings
•Find energy used to condition a
unit volume of air
•Find volume of air exhausted
•Add energy used to condition air
across all units of air exhausted
Estimated Savings
$12,522
21%
•11% of total oil ($7,400)
•7% of total electric. ($10,900)
13%
~$20k
Estimated Implementation Cost
$50k
<2
$17,500—about 1 year payback
$17.5k to Andover
The rest is Rebalance! Was it
needed?